1. Field of the Invention
Disclosed herein is a sound source localization system and method.
2. Description of the Related Art
In general, among auditory techniques for intelligent robots, a sound source localization technique is a technique for localizing the position at which a sound source is generated by analyzing properties of a signal inputted from a microphone array. That is, the sound source localization technique is a technique capable of effectively localizing a sound source generated from a human robot interaction and a place beyond the sight of a vision camera.
FIG. 1 is a diagram showing a related art sound source localization technique using a microphone array.
In related art sound source localization techniques, a microphone array has the form of a specific structure as shown in FIG. 1, and a sound source is localized using such a microphone array. In the technique, a direction angle is mainly detected by measuring a difference in time at which a voice signal reaches each microphone from the sound source. Hence, when using the technique, an object that interrupt the flow of a voice signal between the respective microphones is not necessarily exists so that exact measurement is possible. However, in the case of using two ears of an actual human being, there may occur a problem in the sound source localization technique.
FIG. 2 is a diagram illustrating a problem caused when the related art sound source localization technique is applied to a sound source localization technique using two ears.
Referring to FIG. 2, when the related art sound source localization technique is used in an actual robot technique using two ears, properties of a signal inputted to the two ears from a sound source are changed due to the influence of a face and an ear between microphones, and therefore, performance may be degraded.
A method using a head related transfer function (HRTF) has been proposed so as to solve such a problem. In the method using the HRTF, the influence caused by a platform is removed by re-measuring respective impulse responses based on the forms of the corresponding platform. However, in order to measure impulse responses, signals based on respective directions are necessarily obtained in a dead room, and hence, measurement is complicated whenever the form of the platform is changed. Therefore, the method using the HRTF has a limitation in its application to robot auditory systems with various types of platforms.
In addition, since related art sound source localization systems are sensitively reacted to changes in environment, programs and the like are necessarily modified to make a setting suitable for a change in environment. Therefore, there are many problems in that the related art sound source localization systems are applied to the human robot interaction in which various variables still exist.